Seesaw



3. 0 S LW ,RTA AS CE .,S G

Patented 1390.7, 1897.

WITNEssEs.

LIJ.

3 N 0 S L. Rm AS Gm .S H G PatentedDeo. 7, 1897.

THQ humus PEYERS cu.. FHDTD'LITHQ.. wAsHlNmon n s.

s sheets-sheet 3.

(No Model.)l

SBESAW..

No. 5941.856'. Paten-td Deo; '7,' v1897.

WITNEssEs.

ohms Persa: No., WASHINGTON n c NITE STATES Tirion.

GUSTAF H. CARLSON, OF LOWELL, MASSACHUSETTS.

SEESAW.

SPECIFICATIN forming part of Letters Patent No. 594,856, dated December 7, 1897.

y Application lcd April 19, 1897- SerialNo. 632,899. (No model.)

v of which the following is a specification.

Myinvention relates to seesaws and it consists in the devices and combinations herein described and claimed.

The object of this invention is to enable the seesaw to be operated without the use of the operators feet, to enable one person to use the device without another person to counterbalance his weight, and to enable persons of different Weights to balance each other without adjustment of the fulcrums.

In the accompanying drawings on three sheets, Figure l is a side elevation of a seesaw embodying my improvement; Fig. 2, a

vertical longitudinal central section of the same; Fig. 3, a plan of the same.

A is a base consisting of longitudinal sills a a', resting on blocks d2 a3 d4 a5 (which serve as feet) and supporting a horizontal crossbeam a6. Two parallel vertical posts as a9 are secured to the cross-beam a6 and at their upper ends are connected by ahorizont-al tiebeam a7, which carries on its upper surface, midway between its ends, a vertical fulcrumblock d10, having a vertical longitudinal slit du. The posts as a? are stiffened by inclined braces cl2 a @14 als, which connect them to the sills d a in an obvious manner. Two equal parallel horizontal beams am a are supported on the cross-beam de at right angles thereto inside the posts as a9. p

The above-described parts are rigidly se* cured in place and constitute the stationary frame of the machine, which frame supports the movable parts hereinafter described.

To the beams emanare pivoted four nearly Vertical vibrating standards B B' B2 B3, the lower end of each of said standards being pivoted at o to one of said beams near an end thereof.

To each standard B B' B2B3are pivoted at c c two parallel bars'C C', arranged one above the other, the outer ends of two pairs of such bars beingA pivoted at. c2 o3 to opposite sides of the seat-support D D, each seat-support consisting of two parallel angle-pieces d d',

each having a horizontal part d2 to support a foot-rest E and a vertical part d3, on the top of which a seat F is supported. The seat F may be provided with a cushion f and an upholstered back f The parts d2 d3 of the seatzupzports are preferably connected by braces The upper parallel bars C C at each end of the seesaw are connected in pairs by parallel ties c4 o5, there being two such ties to each pair of upper parallel'bars, the inner ends of said upper parallel bars extending nearly to the posts a8 a9 and beyond the standards B B B2 B3 and the ties c5 being at or near the inner ends of said upper bars C C. On each of the ties c5 c5 is secured a fnlcrumpiece o6 c6, to which is pivoted at g the lower end of a fulcrum-rod G G, the upper end of said rod being pivoted at g' to a-lever I-I, and the latter is pivoted at 7L in the fulcrum-block d10 on the tie-beam al.

The lever H is preferably formed in the three parts, the end portions h' h2 being pivoted to the middle part h3 of 'said lever at h4 h5 and being vertically slotted at 'h6 717 to receive said part h3 to enable said end portions to be raised or lowered, as shown by dotted lines in Fig. 2, to enable a person the more easily to step into the seesaw. The parts h2 h3, when in use, are held rigidly in line with the middle part h3 by pins hs h, passed transversely through the end parts and the middle part across the slot-s h6 7i?. l

Equalizingebars I I are pivoted at their middle points on horizontal pivots t' t" on the posts d8 a9, and the ends of said bars I I are pivoted at 112 i3 to the upper parallel rods C C, between the ends of the latter, to prevent the standards B B B2 B3 from tipping over on their pivots, so that when either end of the lever H rises or falls the seat nearest said end of said lever moves in the opposite direction, and each operator by bearing down on his end of the lever raises his own seat and depresses that of the other operator. The ends of the lever H are provided with horizontal cross-bars hw hu or handles to be grasped by the operators. Y

In order that the difference in weight of the operators may not interfere with the operation of the machine, I use one or more spiral springs J J', two being shown, which connect ICQ the corresponding ends of the two eqnalizingbars with tension-leversj j', each pivoted at one end on the post a8 a and at the other to a te11sionrodj2 each tension-rod having on its under side notches or hooks j'j, which engage horizontal studsjj, projecting from said posts, so that by drawing the tensionrods endwise (to the left in the drawings) the tension-levers are raised and the springs are stretched, with a tendency to raise the adjacent seat and depress the other seat. The heavier person will occupy the seat nearest the springs.

By tightening the springs su flcientl y a per son occupying the seat nearest the spring may operate the seesaw alone. It follows that the other seat, its parallel bars, connecting-rods, and one member ot' each of the eqnalizingbars (the parts to the left of the dotted line in Fig. l) may be omitted when the device is to be used by only one person.

I claim as my inventionl. The combination ofthe frame, vibrating standards, )ivoted thereon, parallel. bars, pivoted at their inner ends on said standards, a seat-frame, pivot-ed to said parallel bars and provided with a seat, equaliZing-bars pivoted on said frame and at their ends pivoted to said parallel bars, an operating-lever, pivoted on said frame and rods connect-ing said lever and said parallel bars.

2. The combination of the frame, vibrating standards, pivoted thereon, parallel bars, pivoted at their inner ends on said standards, a seat-frame, pivoted to said parallel bars and provided with a seat, equaliZing-bars pivoted on said frame and at their ends pivoted to said parallel bars, an operating-lever, pivoted on said frame, rods connecting said lever and said parallel bars, and springs, to raise said equalizing-bars.

3. The combination of the frame, vibrating stan dards,`piv0ted thereon, parallel bars, pivoted at their inner ends on said standards, a seat-frame, pivoted to said parallel bars and pro vided with a seat, equalizing-bars pivoted on said frame and at their ends pivoted to said parallel bars, an operating-lever, pivoted to said frame, rods connecting said operatin glever and said parallel bars, a tension-lever, pivoted on said frame, a spring, connecting said lever and one of said equalizing-bars, a tension-rod, pivoted to the free end of said tension-lever and having notches to engagea stnd on said frame, and said stud, to vary the tension of said spring.

In witness whereof l have signed this specication, in the presence of two attesting witnesses, this 17th day of March, A. D. 1897.

GUS'IAF H. CARLSON.

\Vit11ess'es:

ALBERT M. MOORE, JAMEs JAcQUEs. 

